1 files changed, 159 insertions, 0 deletions
diff --git a/crypto/hmac.c b/crypto/hmac.c
new file mode 100644
index 0000000000..4e6bfa3f09
--- /dev/null
+++ b/crypto/hmac.c
@@ -0,0 +1,159 @@
+/*
+ * (C) Copyright 2015 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ *
+ * GPL v2 only
+ */
+
+#include <common.h>
+#include <digest.h>
+#include <malloc.h>
+
+#include "internal.h"
+
+struct digest_hmac {
+	char *name;
+	unsigned int pad_length;
+	struct digest_algo algo;
+};
+
+struct digest_hmac_ctx {
+	struct digest *d;
+
+	unsigned char *ipad;
+	unsigned char *opad;
+
+	unsigned char *key;
+	unsigned int keylen;
+};
+
+static inline struct digest_hmac * to_digest_hmac(struct digest_algo *algo)
+{
+	return container_of(algo, struct digest_hmac, algo);
+}
+
+static int digest_hmac_alloc(struct digest *d)
+{
+	struct digest_hmac_ctx *dh = d->ctx;
+	struct digest_hmac *hmac = to_digest_hmac(d->algo);
+
+	dh->d = digest_alloc(hmac->name);
+	if (!dh->d)
+		return -EINVAL;
+
+	dh->ipad = xmalloc(hmac->pad_length);
+	dh->opad = xmalloc(hmac->pad_length);
+
+	return 0;
+}
+
+static void digest_hmac_free(struct digest *d)
+{
+	struct digest_hmac_ctx *dh = d->ctx;
+
+	free(dh->ipad);
+	free(dh->opad);
+	free(dh->key);
+
+	digest_free(dh->d);
+}
+
+static int digest_hmac_set_key(struct digest *d, const unsigned char *key,
+				unsigned int len)
+{
+	struct digest_hmac_ctx *dh = d->ctx;
+	struct digest_hmac *hmac = to_digest_hmac(d->algo);
+
+	free(dh->key);
+	if (len > hmac->pad_length) {
+		unsigned char *sum;
+
+		sum = xmalloc(digest_length(dh->d));
+		digest_init(dh->d);
+		digest_update(dh->d, dh->key, dh->keylen);
+		digest_final(dh->d, sum);
+		dh->keylen = digest_length(dh->d);
+		dh->key = sum;
+	} else {
+		dh->key = xmalloc(len);
+		memcpy(dh->key, key, len);
+		dh->keylen = len;
+	}
+
+	return 0;
+}
+
+static int digest_hmac_init(struct digest *d)
+{
+	struct digest_hmac_ctx *dh = d->ctx;
+	struct digest_hmac *hmac = to_digest_hmac(d->algo);
+	int i;
+	unsigned char *key = dh->key;
+	unsigned int keylen = dh->keylen;
+
+	memset(dh->ipad, 0x36, hmac->pad_length);
+	memset(dh->opad, 0x5C, hmac->pad_length);
+
+	for (i = 0; i < keylen; i++) {
+		dh->ipad[i] = (unsigned char)(dh->ipad[i] ^ key[i]);
+		dh->opad[i] = (unsigned char)(dh->opad[i] ^ key[i]);
+	}
+
+	digest_init(dh->d);
+	digest_update(dh->d, dh->ipad, hmac->pad_length);
+
+	return 0;
+}
+
+static int digest_hmac_update(struct digest *d, const void *data,
+			      unsigned long len)
+{
+	struct digest_hmac_ctx *dh = d->ctx;
+
+	return digest_update(dh->d, data, len);
+}
+
+static int digest_hmac_final(struct digest *d, unsigned char *md)
+{
+	struct digest_hmac_ctx *dh = d->ctx;
+	struct digest_hmac *hmac = to_digest_hmac(d->algo);
+	unsigned char *tmp = NULL;
+
+	tmp = xmalloc(digest_length(d));
+
+	digest_final(dh->d, tmp);
+	digest_init(dh->d);
+	digest_update(dh->d, dh->opad, hmac->pad_length);
+	digest_update(dh->d, tmp, digest_length(d));
+	digest_final(dh->d, md);
+
+	free(tmp);
+
+	return 0;
+}
+
+struct digest_algo hmac_algo = {
+	.alloc = digest_hmac_alloc,
+	.init = digest_hmac_init,
+	.update = digest_hmac_update,
+	.final = digest_hmac_final,
+	.set_key = digest_hmac_set_key,
+	.free = digest_hmac_free,
+	.ctx_length = sizeof(struct digest_hmac),
+};
+
+int digest_hmac_register(struct digest_algo *algo, unsigned int pad_length)
+{
+	struct digest_hmac *dh;
+
+	if (!algo || !pad_length)
+		return -EINVAL;
+
+	dh = xzalloc(sizeof(*dh));
+	dh->name = xstrdup(algo->name);
+	dh->pad_length = pad_length;
+	dh->algo = hmac_algo;
+	dh->algo.length = algo->length;
+	dh->algo.name = asprintf("hmac(%s)", algo->name);
+
+	return digest_algo_register(&dh->algo);
+}